For a while, the motto in the sales industry was to be as quick as possible to react to inbound leads. As low as one minute.
Live chat capabilities have reinforced that further.
However in 90% of cases, these knee-jerk reactions to enquiries are done with little value, in a generic way.
My approach is to reply same day, possibly late evening – I work nights.
This ensures proper thoughts have been put into the clients enquiries, in terms of questions to ask, points to position and resources to share.
It provides a feeling that A ) You are busy, hence somewhat successful and B) you have put deep thoughts into your reply, versus a generic quick sales rep reply.
If you walk down the street full of restaurants to choose one, you will prefer instinctively those who seem busy but provide a professional welcome, versus the haranguers/harassers trying to lure you in a seemingly empty restaurant.